A major report on Iarnrod Eireann's intercity service says that some services are performing "extremely poorly" and that slower journey times have to be addressed to get people out of the car and on trains.

The study by AECOM/Goodbody Economic Consultants warns that without service improvements, passenger numbers will not recover before 2015.

It found that in some cases the number of people travelling for free on concessions, like OAP travel passes, meant that the revenue generated was very low.

The study seen by the Irish Independent found that future investment should be on the major routes from Dublin to Cork, Belfast, Limerick, Galway and Waterford.

For a spend of €250m over five years, journey times could be reduced on most routes by 30 minutes, which would make the train competitive with the car.

"It is anticipated that without further service improvements, passenger numbers will not recover from their 2007 peak until after 2015," it warns.

Passenger numbers peaked in 2007 when 10.7 million journeys were made on the inter-city network. This fell to eight million last year.

The major reason for the decline is because the roll-out of the motorway network means it is generally quicker to drive between cities than take the train.

Iarnrod Eireann has spent more than 10 years bringing the network up to a basic standard. Since 1998, more than €1.6bn has been spent upgrading the railway network which includes replacing 500 miles of track, upgrading or closing 900 level crossings and replacing or upgrading 240 bridges.

The fleet is now among the youngest in Europe, and there is spare capacity for more services in Kildare and in Dublin.

By comparison, more than €12bn has been spent upgrading national roads and building motorways between 2006 and 2011.

"Funding then went into things that the customer could see such as new trains and replacement of track.

"Where historically there was an advantage over road, the motorway programme has changed all that. New carriages can do speeds that the network currently doesn't allow. You don't need new trains, you need to invest €50m a year over five years in track and that will knock 30 minutes off journey times."